1-6-2-Bronchogenic carcinoma(types)

1-The most common cause of deaths worldwide.

2-Smoking is considered the major risk factor accounting for 90%.

3-There are three main histological groups:

-Small cell lung cancer.

-Non small cell lung cancer.

*Adenocarcinoma(35%).

*Squamous cell carcinoma(30%).

*Large cell carcinoma(15%).

-Undifferentiated lung cancer.